Question

A sample of coal produces 9 MJ of heat energy on complete combustion of 250 g of coal. The calorific value of coal sample is

• A.
  $36kJ/g$
• B.
  $32kJ/g$
• C.
  $18kJ/g$
• D.
  $25kJ/g$

Answer 1

The correct option is A

$36kJ/g$
26. Heat produced, $H=9MJ=9\times {10}^{6}J$
Mass of the coal,$m=250g$
$\therefore$ Calorific value of coal $=\frac{H}{m}$
$=\frac{9\times {10}^6}{250}J/g=36kJ/g$


Hence, the correct answer is option (a)